I built OasRails, a Rails engine that automatically generates OpenAPI 3.1 documentation from YARD comments in your Rails controllers. It renders the docs using RapiDoc for a slick, interactive UI—no DSLs, no generators, and no dependency on RSpec or Grape.

I was inspired by FastAPI’s interactive docs and wanted something similar for Rails. After not finding anything that met my needs, I built OasRails during downtime as a freelancing dev.